1. Field of the Invention
This invention relates to a filling and packaging machine adapted to make packaging bags from a rolled film and fill the bags with a material.
2. Description of the Related Art
There are known filling and packaging machines as disclosed, for example, in Japanese Patent Laid-Open Nos. 153410/1989, 4626/1990 and 32929/1990, which are adapted to fold in two a film which is continuously fed, superpose edge portions of the folded film on each other and vertically seal the superposed edge portions by a vertical sealing unit, supply a material into the vertically sealed and cylindrically formed film, and package the material by laterally sealing the resultant film by a lateral sealing unit.
In a filling and packaging machine adapted to fill a packaging bag with a liquid as an object material, the material is supplied continuously by operating in general a material supply pump continuously with a vertically sealed and cylindrically formed film also supplied continuously, and the material packed in the film is packaged continuously by sealing the film by a lateral sealing unit. In this machine, the cylindrical film is supplied with the film held between lateral sealing rolls, which are arranged in an opposed state, of the lateral sealing unit. Therefore, even when the liquid, the material to be packed in the film exists between the lateral sealing rolls, it is squeezed out vertically by the lateral sealing rolls, and the film is thermally sealed, whereby the lateral sealing of the film is done.
However, when the liquid, a material to be packed in the film is formed of a highly viscous material of a fluidity or a solid-containing material of a fluidity, the squeezing mentioned above of the material is not done excellently in some cases. Consequently, the material not squeezed out from but residing in the laterally sealed portion is held between the sealed edge sections of the film to cause imperfect sealing of the film to occur. Therefore, such a material could not be applied as it is to the filling and packaging machine.
In order to package such a material, it is necessary to use a filling and packaging machine of the type which is operated by stopping a film, forming a bottom portion of the film by laterally sealing the film, stopping supplying the material after the material has been supplied in a predetermined quantity, feeding the film again and stop the same, and then packaging the material by laterally sealing the portion of the film which is to form a mouth of a packaging bag. In this machine, a n intermittent film transfer system by which the feeding and stopping of the film are done repeatedly is employed, so that a production rate cannot be increased in fact.
The present invention has been made in view of these circumstances, and provides a filling and packaging machine capable of packaging an object material at a high speed without causing a part of the material to be held between the laterally sealed edge sections of a film even when the material is formed of a highly viscous material of a fluidity or a solid-containing material of a fluidity, by feeding the film continuously with the material supplied intermittently.
According to an aspect of the present invention, the filling and packaging machine is adapted to vertically seal a film which is continuously fed, by a vertical sealing unit and thereby form the film into a bottomed cylindrical body, laterally seal the cylindrical film by a lateral sealing unit and thereby form a bottom portion of a packaging bag to be obtained, pack an object material into the bottomed cylindrical film from a filling nozzle disposed in the film, and laterally seal while feeding the film the portion of the film which is to form a mouth of the packaging bag by the lateral sealing unit, whereby the material is packaged continuously, the machine including a material supply unit joined to the filling nozzle and adapted to supply the object material, a detector adapted to detect the lateral sealing time of the lateral sealing unit, and a control unit for having the material supplied intermittently by starting a material supplying operation of the material supply unit when a predetermined period of time has elapsed after the generation of an output signal in the lateral sealing time detector, continuing the supplying of the material for a predetermined period of time and then stopping supplying the material. Owing to this arrangement, the material can be packaged at a high speed without causing a part of the material to be held between the sealed edge portions of the film, by intermittently supplying the material with the film fed continuously.
According to another aspect of the present invention, the filling and packaging machine is adapted to vertically seal a film which is continuously fed, by a vertical sealing unit and thereby form the film into a bottomed cylindrical body, laterally seal the cylindrical film by a lateral sealing unit and thereby form a bottom portion of a packaging bag to be obtained, pack an object material formed of a highly viscous material of a fluidity or a solid-containing material of a fluidity into the bottomed film from a filling nozzle disposed in the film, and laterally seal while feeding the film the portion of the film which is to form a mouth of the packaging bag by the lateral sealing unit, whereby the material is packaged continuously, the machine including a material supply unit joined to the filling nozzle and adapted to supply the object material, a detector adapted to detect the lateral sealing time of the lateral sealing unit, and a control unit for having the material supplied intermittently by controlling the material supply unit on the basis of the material supplying starting time between the time of the reception of an output signal from the lateral sealing time detector and that of starting supplying the material, and the material supplying continuation time between the time of starting supplying the material and that of stopping supplying the material.
Accordingly, in the present invention, the timing of the starting of the material supplying operation by the material supply unit and the time between the time of starting of the material supplying operation and that of the stopping thereof, i.e. the material supplying continuation time are set on the basis of an output signal from the lateral sealing time detector.
Namely, this filling and packaging machine is formed so that the supplying of the material is stopped when the film continuously fed is subjected to a lateral sealing operation of the lateral sealing units, with the material supplied when a predetermined period of time has elapsed after the completion of the lateral sealing operation, and so that the supplying of the material can be stopped by the time a subsequent lateral sealing operation has been started, by setting the time during which the supplying of the material is done, i.e. the material supplying continuation time. Therefore, the material can be packaged at a high speed without causing a part of the material to be held between the laterally sealed edge sections of the film.
This filling and packaging machine is provided with a material supplying condition setting unit for setting at least one of the material supplying starting time and material. supplying continuation time on the basis of the packaging conditions for each kind of packaging bag, i.e., a material supplying condition setting unit for inputting the material supplying starting time and material supplying continuation time on the basis of the packaging conditions for each kind of packaging bag, i.e. the packaging conditions which include a film feeding speed, intervals at which packaging bags are formed and an amount of material to be packed in a cylindrical film by the material supplying unit, and which differ depending upon the kind of the packaging bag. Therefore, the supplying of the material by the material supply unit is controlled on the basis of the set values or the material supplying starting time and material supplying continuation time calculated on the basis of the set values.
This filling and packaging machine is also provided with a storage unit for storing the conditions set by this material supplying condition setting unit, so that it is possible to set the material supplying starting and stopping timing of the material supply unit in accordance with the packaging conditions which differ depending upon the kind of the packaging bag in which the material is to be packaged, and then store such data in the storage unit; readout as necessary the material supplying starting time and material supplying continuation time stored in the storage unit and matching each of the packaging conditions; and thereby automatically set the material supplying starting and stopping timing of the material supply unit.
The lateral sealing unit is formed of a pair of sealing plate-carrying lateral sealing rolls, while the lateral sealing time detector is formed of portions to be detected which are adapted to be rotated with the lateral sealing rolls, and which are provided correspondingly to the positions in which the seal plates are provided, and a detecting member for detecting the portions to be detected, the object material being supplied intermittently via a control unit on the basis of a signal from the detecting member.